Violet electroluminescence from poly(N-vinylcarbazole)/ZnO-nanrod composite polymer light-emitting devices

In this paper, we have demonstrated the violet electroluminescence (EL) of poly(N-vinylcarbazole) (PVK) and ZnO-nanorods composite polymer light-emitting device (PLED). The structure of PLED is PVK/ZnO-nanorods composite layer sandwitched between an anode and a cathode. The composite layer is made by mixing PVK and semiconducting ZnO nanorods with proper weight (wt.) ratio. Furthermore, the nanometer scale polyethylene oxide (PEO) is inserting as a modified cathode. The PEO film is deposited by thermal evaporation. Composite PLED appears violet emission with a main 440 nm EL peak, attributed to singlet excimer. A 607 nm EL peak is exhibited from triple excimer of the composite PLED. Both the main EL peak intensity and the triple EL peak intensity of composite PLED are enlarged by incorporating ZnO nano-materials into PVK.